Question

A body projected upward from the level ground at an angle of 50° with the horizontal has an initial speed of 40 m/s. (a) How long will it take to hit the ground? (b) How far from the starting point will it strike? (c) At what angle with the horizontal will it strike?

Answer 1

✌A body projected upward from the level ground at an angle of 50° with the horizontal has an initial velocity of 40 m/s. How long will it be before it hits the ground? How far from the starting point will it strike?

❣Explanation:

For the 1st part we can use:

➡$u = v + at$

If we consider only the vertical component of motion this becomes:

➡$0 = v \sin(50) - gt$

➡$t = \frac{40 \sin(50) }{9.8} = 3.12sec$

This is the time taken for the body to reach its maximum height.

To fall to the ground takes the same amount of time so we can say:

➡$t = 3.126 \times 2 = 6.25sec$

To get the range we consider the horizontal component of motion.

The velocity in the x direction is constant so we can say:

➡$s = \frac{d}{t}$

➡$d = s \times t$

➡$40 \cos(50) \times 6.25 = 160.7m$

❤❤BTS AND EXO❤❤

Answer 2

Given : Body projected upward from the level ground at an angle of 50° with the horizontal has an initial speed of 40 m/s.

To Find : (a) How long will it take to hit the ground?

               (b) How far from the starting point will it strike?

Solution :

(a) For the 1st part we can use:

$\[v = u + at\]$

If we consider only the vertical component of motion this becomes as v = 40 m/s :

$\[0 = v\sin (50^\circ ) - gt\]$

$\[t = 3.12\sec \]$  

This is the time taken for the body to reach its maximum height.

To fall to the ground takes the same amount of time so we can say:

$\[t = 3.126 \times 2\sec = 6.25\sec \]$

(b) To get the range we consider the horizontal component of motion.

The velocity in the x direction is constant so we can say:

$\[s = \frac{d}{t}\]$

$\[d = s \times t\]$

$\[d = 40\cos (50^\circ ) \times 6.25 = 160.67m\]$.

Hence (a) Time taken to hit the ground is 6.25 sec (b) Horizontal distance from starting point to when it strike is 160.67 m